1. Field
The field of the invention is breath operated blowguns and darts and more particularly those adapted for sporting target use.
2. State of the Art
Relatively crude breath operated dart guns are common in primitive societies as hunting weapons for game, the larger game generally requiring a poisoned dart for lethal effect. These devices, are made from naturally occurring materials and are of limited range and accuracy. Certain primitive blowguns are known to be constructed of two pieces of wood, each semicircularly grooved and subsequently joined by glue to provide an elongate bore of approximately uniform diameter. These devices tend to have rough bores, spoiling dart velocity and range. Further, they are easily damaged by rough handling, and are susceptible to moisture and heat warpage. The projectiles are best characterized as miniature arrows, having elongate wooden shafts and feather stabilizers. They are not efficiently launched by the breath of the user. Launching tubes of steel, copper, or aluminum are similarly not suitable for long range and high accuracy. They are either excessively limber or too heavy for accurate aiming, tubes with thin walls for acceptable weight being too limber and further easily dented and bent. The cost of more rugged, highly tempered metal is prohibitive. Extruded tubes of unreinforced plastic are similarly fragile and are not sufficiently stable dimensionally, tending to warp or flatten with the passage of time, becoming unuseable, or at least of reduced range and accuracy. Launching tubes constructed by winding of resin impregnated filament tape about an elongate mandrel are stronger and more stable, but are also quite expensive. Very expensive composite launch tubes of plastic with an outer shell of metal, although quite rigid, are too heavy for the easy handling needed for accurate target use.
The conventional feather stabilized dart is not well adapted for maximum range and accuracy. The feather members, longitudinally aligned and presenting minimum frontal area, inefficiently utilize the propulsive power of the expelled air, since the air flows largely unused around the stem through the spaces between the feather elements. The feather elements cause unwanted friction within the launching tube, shortening the range. They are fragile and therefore not well adapted to repeated use. The shafts are of wood or plastic, and must be, for strength and dimensional stability, of relatively large diameter, and contribute substantially to aerodynamic drag, shortening the range.
These shortcomings in the prior art have long frustrated efforts to produce easily handled dart blowguns sufficiently accurate for target use capable of manufacture at reasonable cost.